fix: print() multiline behaviour

.changeset/rich-zoos-walk.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: multiline html blocks now properlery seperated from other multiline blocks while `print()`-ing an AST

packages/svelte/package.json

@@ -176,7 +176,7 @@
     "clsx": "^2.1.1",
     "devalue": "^5.5.0",
     "esm-env": "^1.2.1",
-    "esrap": "^2.2.1",
+    "esrap": "https://pkg.pr.new/sveltejs/esrap@101",
     "is-reference": "^3.0.3",
     "locate-character": "^3.0.0",
     "magic-string": "^0.30.11",

packages/svelte/src/compiler/print/index.js

@@ -115,56 +115,16 @@ function base_element(node, context) {
 
 	const is_self_closing =
 		is_void(node.name) || (node.type === 'Component' && node.fragment.nodes.length === 0);
-	let multiline_content = false;
 
 	if (is_self_closing) {
 		child_context.write(`${multiline_attributes ? '' : ' '}/>`);
 	} else {
 		child_context.write('>');
-
-		// Process the element's content in a separate context for measurement
-		const content_context = child_context.new();
-		const allow_inline_content = child_context.measure() < LINE_BREAK_THRESHOLD;
-		block(content_context, node.fragment, allow_inline_content);
-
-		// Determine if content should be formatted on multiple lines
-		multiline_content = content_context.measure() > LINE_BREAK_THRESHOLD;
-
-		if (multiline_content) {
-			child_context.newline();
-
-			// Only indent if attributes are inline and content itself isn't already multiline
-			const should_indent = !multiline_attributes && !content_context.multiline;
-			if (should_indent) {
-				child_context.indent();
-			}
-
-			child_context.append(content_context);
-
-			if (should_indent) {
-				child_context.dedent();
-			}
-
-			child_context.newline();
-		} else {
-			child_context.append(content_context);
-		}
-
+		block(child_context, node.fragment, true);
 		child_context.write(`</${node.name}>`);
 	}
 
-	const break_line_after = child_context.measure() > LINE_BREAK_THRESHOLD;
-
-	if ((multiline_content || multiline_attributes) && !context.empty()) {
-		context.newline();
-	}
-
 	context.append(child_context);
-
-	if (is_self_closing) return;
-	if (multiline_content || multiline_attributes || break_line_after) {
-		context.newline();
-	}
 }
 
 /** @type {Visitors<AST.SvelteNode>} */
@@ -387,6 +347,8 @@ const svelte_visitors = {
 				}
 			} else {
 				sequence.push(child_node);
+
+				if (child_node.type === 'RegularElement') flush();
 			}
 		}
 
@@ -395,18 +357,20 @@ const svelte_visitors = {
 		let multiline = false;
 		let width = 0;
 
-		const child_contexts = items.map((sequence) => {
-			const child_context = context.new();
+		const child_contexts = items
+			.filter((x) => x.length > 0)
+			.map((sequence) => {
+				const child_context = context.new();
 
-			for (const node of sequence) {
-				child_context.visit(node);
-				multiline ||= child_context.multiline;
-			}
+				for (const node of sequence) {
+					child_context.visit(node);
+					multiline ||= child_context.multiline;
+				}
 
-			width += child_context.measure();
+				width += child_context.measure();
 
-			return child_context;
-		});
+				return child_context;
+			});
 
 		multiline ||= width > LINE_BREAK_THRESHOLD;
 

packages/svelte/tests/print/samples/formatting/input.svelte

@@ -1 +1,8 @@
-<script>import { setLocale } from '$lib/paraglide/runtime';import { m } from '$lib/paraglide/messages.js';</script><h1>{m.hello_world({ name: 'SvelteKit User' })}</h1><div><button onclick={() => setLocale('en')}>en</button><button	onclick={() => setLocale('es')}>es</button></div><p>If you use VSCode, install the <a href="https://marketplace.visualstudio.com/items?itemName=inlang.vs-code-extension" target="_blank">Sherlock i18n extension</a>for a better i18n experience.</p>
+<script>import { setLocale } from '$lib/paraglide/runtime';import { m } from '$lib/paraglide/messages.js';</script>
+
+<h1>{m.hello_world({ name: 'SvelteKit User' })}</h1><div><button onclick={() => setLocale('en')}>en</button><button	onclick={() => setLocale('es')}>es</button></div><p>If you use VSCode, install the <a href="https://marketplace.visualstudio.com/items?itemName=inlang.vs-code-extension" target="_blank">Sherlock i18n extension</a>for a better i18n experience.</p>
+
+<Component><div><button>Hello, this is a test</button><button>Hello, this is a test</button></div></Component>
+<Component><button>Hello, this is a test</button><button>Hello, this is a test</button></Component>
+<button class="foo bar" aria-label="click" onclick={() => console.log("clicked")}>Click me!</button>
+<button class="foo bar" aria-label="click" onclick={() => console.log("clicked")}><span>some fancy looking</span><span>really long button text</span></button>

packages/svelte/tests/print/samples/formatting/output.svelte

@@ -4,18 +4,46 @@
 </script>
 
 <h1>{m.hello_world({ name: 'SvelteKit User' })}</h1>
+
 <div>
 	<button onclick={() => setLocale('en')}>en</button>
 	<button onclick={() => setLocale('es')}>es</button>
 </div>
+
 <p>
 	If you use VSCode, install the 
 
 	<a
 		href="https://marketplace.visualstudio.com/items?itemName=inlang.vs-code-extension"
 		target="_blank"
-	>
-		Sherlock i18n extension
-	</a>
+	>Sherlock i18n extension</a>
+
 	for a better i18n experience.
 </p>
+
+<Component>
+	<div>
+		<button>Hello, this is a test</button>
+		<button>Hello, this is a test</button>
+	</div>
+</Component>
+
+<Component>
+	<button>Hello, this is a test</button>
+	<button>Hello, this is a test</button>
+</Component>
+
+<button
+	class="foo bar"
+	aria-label="click"
+	onclick={() => console.log("clicked")}
+>Click me!</button>
+
+<button
+	class="foo bar"
+	aria-label="click"
+	onclick={() => console.log("clicked")}
+>
+	<span>some fancy looking</span>
+	<span>really long button text</span>
+</button>

packages/svelte/tests/print/samples/style-directive/output.svelte

@@ -1,8 +1,7 @@
 <div style:color="red">...</div>
+
 <div
 	style:color
 	style:width="12rem"
 	style:background-color={darkMode ? 'black' : 'white'}
->
-	...
-</div>
+>...</div>

packages/svelte/tests/print/samples/svelte-fragment/output.svelte

@@ -4,6 +4,7 @@
 
 <Widget>
 	<h1 slot="header">Hello</h1>
+
 	<svelte:fragment slot="footer">
 		<p>All rights reserved.</p>
 		<p>Copyright (c) 2019 Svelte Industries</p>

packages/svelte/tests/print/samples/svelte-head/output.svelte

@@ -1,5 +1,6 @@
 <svelte:head>
 	<title>Hello world!</title>
+
 	<meta
 		name="description"
 		content="This is where the description goes for SEO"